Wheel-feeding cam for circular knitting machines

ABSTRACT

A circular knitting machine with pattern wheels is provided with wheel-feeding cams which guide the butts of needles into pattern wheel slots. Each such wheel-feeding cam preferably includes an extension running parallel to a pattern wheel and effective to lock needle butts in their pattern wheel slots.

United States Patent [191 Mishcon et al.

[ WHEEL-FEEDING CAM FOR CIRCULAR KNITTING MACHINES [75] Inventors: Lester Mishcon, Miami Beach;

Donald W. Reagan, Hialeah, both of Fla.

[73] Assignee: The Singer Company, New York,

221 Filed: June 9, '1972 [2]] Appl. No.: 261,456

[52] U.S. Cl. 66/50 A, 66/57 [51] Int. Cl D04b 15/76 [58] Field of Search 66/50 A, 50 R, 50 B, 25, 36 A,

[56] References Cited UNITED STATES PATENTS 3,513,666 5/1970 Mishcon 66/50 A [451 Feb. 26, 1974 3,595,033 7/1971 Agulnek 66/50 A 2,006,821 7/1935 Agulnek 66/50 A 3,457,736 7/1969 Mishcon 66/50 A 3,614,877 10/1971 Radin 66/50 A Primary Examiner lames Kee Chi Attorney, Agent, or FirmMarshall .1. Breen; C. A. Williams, Jr.; W. V. Ebs

[57] ABSTRACT 6 Claims, 5 Drawing Figures all WHEEL-FEEDING CAM FOR CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to circular knitting machines with pattern wheels and especially to fine gauge pattern wheel circular knitting machines.

2. Description of the Prior Art In pattern wheel circular knitting machines the needles are lifted by raise cams to dispose needle butts relative to pattern wheels such that butts may enter successive slots in each pattern wheel as the needle carrying cylinder and cams of the machine move relative to each other. Whether any particular needle knits, tucks, or welts is determined by the presence of a high jack, low jack or the absence of any jack from the pattern wheel slot with which the needle registers. It is therefore essential that each needle butt enters the slot intended for it, and also that it remains in the proper slot while in the pattern wheel.

In machines wherein the needles are relatively far apart and the pattern wheel slots are correspondingly far apart, even if some needle butts do not enter their pattern wheel slots at precisely the point intended relative to needle actuating camming due to their being carried by momentum to heights greater than that to which they are lifted by the raise cam, such needles ordinarily do enter their pattern wheel slots a slight distance beyond the intended point of entrance, and such needles function in an acceptable manner. However, in fine cut machines wherein needles are closely packed around the cylinder of a machine and pattern wheel slots are close together with only fine walls separating them, if needle butts do not enter the pattern wheel slots intended for them at the proper point they may never do so. Because of the narrow'slots, a slightly bent needle, a somewhat distorted upper portion of the wall of a slot, or dirt in a slot may result in a needle being carried to or above the knit position even though such needle should welt or tuck.

In addition, in fine cut machines, it not infrequently happens, that the required timing relationship between needle butts and pattern wheels is upset, due, for example to needle butts being cammed by and over slot walls of pattern wheels as when the machine is started or stopped or the speed suddenly changed, the needle butts thereupon moving from their proper slots into adjacent slots.

SUMMARY OF THE INVENTION In accordance with the invention a pattern wheelfeed-ing cam is provided which guides needle butts into pattern wheel slots intended for them. The wheelfeeding cam extends from a point over a raise cam to a point where butts of needles which are at a predetermined maximum height to which they are brought by the raise cam enter their pattern wheel slots. The cam by reason of being engageable with needle butts between such positions prevents the uncontrolled upward flight of needles and serves to guide the needles into their pattern wheel slots. Preferably the wheel-feeding cam also extends parallel to its associated pattern wheel some distance beyond the aforesaid position in which the needle butts enter the pattern wheel slots to thereby lock needle butts in their pattern wheel slots and so prevent relative movement of a pattern wheel and needles, and the skipping of needles from one pattern wheel slot to another due to sudden starts or stops of the machine.

DESCRIPTION OF THE DRAWINGS section and showing a modified wheel-feeding cam.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 through 3 of the drawings, reference character 10 represents a cam section block for a circular knitting machine as described for example,

'in US. Pat. No. 3,513,666 for Circular Knitting Machine with Pattern Wheels issued May 26, 1970 to Lester Mishcon.

As shown such cam section block includes needle actuating cams comprising a raise cam 12, a placer cam 14, stitch cam 16, a guard cam 18 located over the raise and placer cams, and a wing cam 20 located under the stitch cam 16. A pattern wheel 22 is mounted as in the manner described in the aforesaid patent on a fork 24 affixed to the cam section block. The pattern wheel 22 is rotatable in a plane which is at an acute angle with the vertical and includes slots 26 skewed with respect to its plane of rotation, the skewing and rotating planes being such that the pattern wheel slots may fully intermesh with needles when such slots are vertically disposed and adjacent a needle carrying cylinder. Each pattern wheel slot may as in conventional be filled with a high jack 28 or with a low jack 30, or with no jack depending upon whether it is intended to raise a needle to knit, tuck or welt knitting height.

Cam section block 10 includes a retractable wheelfeeding cam 32. The cam 32 is supported on an arm 34 that is slidably mounted in a slot 35 on fork 24 by means of screw 36 extending through a slot 38 in the arm 34 and into the fork. A recess 40 is provided in the edge of arm 34 to receive a tab 42 located on a flexible member 44 which is affixed by screw 46 to fork 24.

Cam section block 10 is one of a plurality of like cam section blocks to be provided around the cylinder of a circular knitting machine and in FIG. 1 there may be seen one such additional block 10' adjacent to the block 10. The cam section block 10' includes a pattern wheel and camming corresponding to the pattern wheel and camming of section block 10, and such parts on the block 10 are designated by the same reference characters as the corresponding parts on the block 10 except for the addition to the reference characters used on block 10 of a prime mark.

The wheel-feeding cams on the cam section blocks cooperate with upper butts 48 of the two butt needles 50 of which several may be seen in section block 10', and the other cams cooperate with the lower butts 52 of the needles. The pattern wheels cooperate with the upper butts 48. A wheel-feeding cam on one cam section block when in an operating position overlies slots of the pattern wheel mounted on the adjacent cam section block. Referring in particular to wheel-feeding cam 32 which is shown in its operating position as defined by the presence of the tab 42 in recess 40, it may be seen that the cam overlies slots at the edge of the pattern wheel 22'.

Wheel-feeding cam 32 is at the level of the top of the upper butt 48 of a needle 50 which is at the maximum height to which it may be raised by raise cam 12', and in its operating position extends over needle slots in pattern wheel 22' from a point over the top of the raise cam 12' to a location wherein said upper butts enter their pattern wheel slots (see FIG. 3). Preferably the wheel-feeding cam extends horizontally as shown in the drawings. The point over the raise cam 12' from which the wheel-feeding cam extends may be at the extreme upper end of the inclined slope of the raise cam, or such point may be so located that the wheel-feeding cam extends over a substantial portion of the raise cam. Preferably the wheel-feeding cam 32 is provided with an extension 54 running parallel to pattern wheel 22 for some distance beyond the aforesaid location wherein upper needle butts enter their pattern wheel slots.

The wheel-feeding cam 32 by maintaining contact with the top of the upper butt of needles prevents needles from being carried by their own momentum to heights higher than that to which they are raised by the raise cam 12' and guides the needle butts 48 into their pattern whee] slots. The parallel extension 54 locks needles in their pattern wheel slots for a period of time to prevent relative movement of the wheel and needles and the skipping of needles from one slot to another.

FIG. 4 shows a modified form of wheel-feeding cam 56 on a cam section block a which is similar to the cam section block 10 already described. The cam section block 100 is shown with cams, a pattern wheel and cooperating needles corresponding to the parts already referred to, and parts in FIG. 4 corresponding to parts already described bear the same reference characters except for the addition of small letter a. In cam section block 10a a wheel-feeding cam 56 which is integral with the guard cam 18a guides the needles into the pattern wheel 22a which is on the block. As shown, such wheel-feeding cam cooperates with the lower butts 52a of needles 50a rather than with the upper butts 48a. The wheel-feeding cam 56 is at the level of the top of the lower butt 52a of a needle 50a when such needle is at the maximum height to which it may be raised by raise cam 12a and extends horizontally beyond a location over the end of the raise cam to a location wherein the upper needle butts enter their pattern wheel slots. Preferably the wheel-feeding cam is provided with an extension 58 running parallel to pattern wheel 22a for the purpose of locking needles in their pattern wheel slots. It is preferable that the guard cam be mounted in the cam section 1021 as in the manner of US. Pat. No. 3,595,033 issued July 27, 1971 to Harry Agulnek so that the guard cam 18a, wheel-feeding cam 56 and extension 58 may be retracted to facilitate the timing of pattern wheels on a machine and the replacement of damaged needles. As noted hereinbefore in connection with the description of cam section block 10, arm 34 which supports the wheel-feeding cam 32 is slidable on fork 24. Arm 34 includes pin 60 and the wheel-feeding cam 32 with its extension 52 may therefore be retracted by pulling with a suitable tool on pin 60 from the side of the cam section block opposite to the side on which the cams are situated, tab 42 being cammed out of recess 40 in the process.

While the invention has been described in its preferred form, it is to be understood that the words which have been used are words of description rather than of limitation, and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention.

Having thus set forth the nature of this invention, what is claimed herein is: v

1. In a circular knitting machine, the combination comprising a plurality of knitting needles, a rotatably mounted pattern wheel inclined with respect to the needles, said needles at least including butts to engage the pattern wheel, a raise cam for raising needles to a predetermined height upon relative motion of the raise cam and needles, and a wheel-feeding cam to engage said needles after they have been lifted to said predetermined height and guide the said needle butts into their pattern wheel slots, the wheel feeding cam extending at uniform height from a point over the raise cam in the direction of movement of needles relative to cams for the distance required to limit the height of the needles to said predetermined height and maintain engagement with the needles until said needle butts enter their pattern wheel slots.

2. The combination defined in claim 1 wherein the needles include butts additional to the butts engageable with the pattern wheel and the wheel-feedin g cam is engageable with the additional needle butts.

3. The combination of claim 1 wherein the wheelfeeding cam is retractable.

4. The combination defined in claim 1 wherein the wheel-feeding cam includes an extension running parallel to the pattern wheel beyond the position wherein the said needle butts enter their pattern wheel slots.

5. The combination as defined in claim 4 wherein the needles include butts additional to the butts engageable with the pattern wheel, and the wheel-feeding cam including said extension is engageable with said additional needle butts. v

6. The combination of claim 4 wherein the wheelfeeding cam and said extension are retractable. 

1. In a circular knitting machine, the combination comprising a plurality of knitting needles, a rotatably mounted pattern wheel inclined with respect to the needles, said needles at least including butts to engage the pattern wheel, a raise cam for raising neEdles to a predetermined height upon relative motion of the raise cam and needles, and a wheel-feeding cam to engage said needles after they have been lifted to said predetermined height and guide the said needle butts into their pattern wheel slots, the wheel feeding cam extending at uniform height from a point over the raise cam in the direction of movement of needles relative to cams for the distance required to limit the height of the needles to said predetermined height and maintain engagement with the needles until said needle butts enter their pattern wheel slots.
 2. The combination defined in claim 1 wherein the needles include butts additional to the butts engageable with the pattern wheel and the wheel-feeding cam is engageable with the additional needle butts.
 3. The combination of claim 1 wherein the wheel-feeding cam is retractable.
 4. The combination defined in claim 1 wherein the wheel-feeding cam includes an extension running parallel to the pattern wheel beyond the position wherein the said needle butts enter their pattern wheel slots.
 5. The combination as defined in claim 4 wherein the needles include butts additional to the butts engageable with the pattern wheel, and the wheel-feeding cam including said extension is engageable with said additional needle butts.
 6. The combination of claim 4 wherein the wheel-feeding cam and said extension are retractable. 